Add SCA user on multiple SharePoint Site collection

<#
******-----------------------------------------------------------------------******
Author          -> Shiv Mangal Singh
Date            -> 25th Jan - 2016
Description     -> This script will add user as SCA on multiple Site collection level.
             

$data = Get-Content "D:\contosoMWteam\shiv\ps\siteurl.txt" here siteurl.txt file contains site collection Url.
******-----------------------------------------------------------------------******
 #>
Add-PSSnapin microsoft.sharepoint.powershell -ErrorAction SilentlyContinue

    $data = Get-Content "D:\contosoMWteam\shiv\ps\siteurl.txt"
# Iterate site collection from $data
    Foreach($site in $data)
    {
      write-host $site
      New-SPUser -UserAlias 'r1-core\shrsachd' -DisplayName 'Shraddha Sachdev' -Web $site -SiteCOllectionAdmin
    }